This invention relates to an idler roller particularly for a belt conveyor.
Several types of idler rollers are utilised in the converyor industry including transporting idler roller, return idler rollers and impact idler rollers. Conventionally, these idler rollers comprise a tubular roller body having a bore to accommodate an idler shaft and bearing assemblies located at each end of the roller body for mounting the idler shaft. The roller body may be constructed of steel or plastic material. Plastic roller bodies have the advantage that they are lighter than steel roller bodies but have the disadvantage that there may be a build-up of electrostatic charge on the surface of the roller body which may affect the operation of the idler roller.
South African Pat. No. 80/6608 (and corresponding U.S. Pat. No. 4,440,295) discloses an idler roller which comprises a prefabricated core having a bore to accommodate an idler shaft, and a shell of synthetic plastic material moulded around the core to provide a tubular load-bearing wall and end walls integral therewith. In the specification of this patent, it is stated that metallic additives or inserts may be used in the roller which would serve to prevent build-up of static by draining any charge formed via the bearings and the idler roller shaft. However, this patent does not give any guidance as to the form or construction of such metallic additives or inserts or how they may be included in the idler roller.